Projectile fuse



L. K. LILJEGREN PROJECTILE FUSE Get. 3, 1950 2 Sheets-Sheet 1 Filed May 22, 1945 1 mam); 176w Oct. 3, 1950 I LILJEGREIN 2,524,060

PROJECTILE FUSE Filed May 22, 1945 sheets sheet 2 w K- fl 'a Patented Oct. ;i 11.;

UNITED STATES PATENT QFF'ICE 2524;066 w PitoJfioTiLE FUs'iji Lyle'Ki Liljegren, Silver Spring, Md Application May 2 l 5ifs r fi i 355 36 fl aims- (01.; le -1 1st (Granted; merits. act tenders-188a, is

The invention described herein may bemanufactured and used by or'for the Government for governmental purposes without thetpayment'to me of any royalty thereon. 1 V

This invention relates toan 'improved..delay arming projectile fuze, and more particularly; to a fuze for use with nonrotating type projectiles.

It is a primary object of this invention to'provide a fuze for nonrotating type projectilesw-hich will remain in a safe or disarmed conditionduring the initial stage of its flight and which will arm only after the fuze and theprojectile,1in which it is contained;-has traveled'a' sufficiently distance from the weapon from which it isfire'd,

so that detonation of the fuze would not endanger the gun crew. g

Another object of the invention is toprovide a fuze which is actuated, for arming the fuze, by means incident to the flight thereof so that little projectile, in the initial part of its flight, should strike a mask or a tree, burst of the shell would not result.

More particularly, it is an object of the-invention to provide a detonator carrier which is spring urged, selectively, for aligning either of two-or more detonators with a flash passage, and which is so constructed that a portion of the flash passage will initially function to retain the'detonator carrier in an intermediate, safe position;-

Still a further aim of the invention is -to provide a fuze having a firing pin which is-rotatably connected to an arming vane and connected by spring means to a portion-of the fiash'-'p'assage, so that upon being actuated by the-arming 'va ne,

it will function for retracting said portion of the flash passage into a position topermit arming of the fuze. j Other objects and advantages of the-invention will hereinafter become more fully apparent from the following description of the drawings, whichrillustrates preferred embodiments thereof, and wherein:

Figure 1 is a longitudinal, substantially central sectional view, of a tune constructedin"accordadjacentiits rear end and seats, atitsreargen an annular stepsor'shoulder 2?: of the boregEfl,

amended April- 30, 192s; 370 0. 9,757);

. Figure lxlis aiplan view of: thedetonatorparrier or rotor, showndetached. 1" ,s ;l,- l Figures8 and: 9 ..ar.e.transversesectionalyiews takenl- 'substantially along lihfiliplallfis o t er n 8-58 and 9=-9,.;respective1y. of Figure}; l

Figur w is ;a fragmentary side eleyational view t upp r portion'eof the fuze housin I I one eleigure 11 is a sideflelevational view of mentofthe fuze; a I

Figure 12 is .antendyiew, in'jelevation thereof,

i Referring ..1 'nore V particularly. to the drawings,

wherein like reference characters designate l k :orcorresponding: parts throu hout the several views; l 5 designates generally: the improved fuze in, its entirety and which includesa housin designated generally. 516;- .the forward. end of which; prior to.firing, is infclosed withina removble cup-shapedgcover I].

' "The housing 16, adjacentits rear end, is provided with an externally threaded portion [8 V which is adapted to threadedly engage in the nose of a nonrotatingtype projectile, not shown, such as a mortarshell, for detachably mounting the fuze l5..'0n the, forward end thereof. Rearwardly of thethreaded portion. [8, the housing It is provided with a rearwardly opening chamber I9 which has a threaded rearlend inwhich is detachably mounted a cup -shapedbooster charge 21. provided with a' central opening 22' which is normally closed by cup-shaped member 213 which containsa: small quantity of; a relatively sensitive explosive. 1 :1' r V 1:;

' Thehousing Ifilis provided with an axially dispcsedwboren 24 which? opens outwardly of the threaded nipple 25-,at the forward end-thereof, and which'ais provided with a restricted rear: end which-opens into the inner part ofthe chamber 19; A tube: orsleeve 26 ismounted in thebore f to 24..andiextendslfrom'the forward end thereo The .rear end ofr thezsleveve 261s internally threaded at 28 to engageta threaded, portion 2,9 ofia; .or .fiash't'tube 30, which. is disposed therewithin.

--:?Iihe threaded portionjwifi isg-likewise disposed at Fith rear end of the sleeve 30.} The sleeve 30, at its. rear end, is provided with an integral hollow stem 31 which projects: through the restricted rear endof :theborer24 and into'the chamber 19.

The innerend of the stem 3| is counterbored to receive a primer 32 which opens into theiinterior shoulderi.33i formed by the restricted portion of The inner. wall'ofsthe booster charge 2| is V sleev 'cumferentially spaced from one another.

the bore 24 to limit the extent to which the stem extends into the chamber l9, so that when the sleeve 33 is in its rearmost position, as seen in Figure 1, the rear end of the stem 3| terminates in spaced relationship to the cup 23, with which it is in alignment. The outer sleeve 26 is provided with an elongated opening 34 and the inner sleeve 30 is provided with a plurality "of openings 35 which are spaced circumferentially and longitudinally thereof.

A cap 36 is provided with an internally threaded recess 31 for engaging the nipple 25 and forms the detachable forward end of the housing l6 and is provided with a forwardly extending centrally disposed nipple 38 which has a bore 39 extending therethrough and opening into the recess of the cap 36. The bore 39 forms a bearing for a shaft 40 which is rotatably disposed therein and which is provided with a threaded forward end 4! which is engaged by a threaded hub 42 of an arming vane 43. A helical spring 44 surrounds a portion of the shaft 40 and the nipple 38 and is disposed between the cap 36 and a collar 45. The collar 45 and a flange of the hub 42 form races for antifriction bearings 46 to mount the arming vane 43 for relatively free rotation relatively to the spring 44. The rear end of the shaft 45 is'disposed within the sleeve 26 and is enlarged to form an annular forwardly facing shoulder 41 which bears against a washer 'or collar 48 which is mounted on the restricted portion of the shaft 40; The rear end of the enlarged portion of the shaft 40 extends into the forward end of the sleeve 30 and terminates in a restricted tapered projection firing pin 49 which is axially disposed in alignment with the primer 32. Between the sleeve 36 and the collar 48, a helical spring 50 is disposed around the enlarged portion of the shaft 45 and has its forward end anchored in a recess in said shaft and its rear end anchored in the sleeve 30.

The forward portion of the cap 36 is provided with a transverse bore which registers with a transverse opening 52 in one position of the shaft 40, for receiving a cotter pin 53 having a ring 54 connected to the eye thereof. The cotter pin 53 forms a safety pin to hold the shaft 45 against sliding or rotary movement.

The housing i6 is provided with a bore 55 which is disposed oif center thereof and which extends longitudinally of the housng. The rear end of bore 55 is counterbored and opens into the chamber l9 and the forward end thereof opens into a portion of the annular shoulder of the housing l6 which surrounds the nipple 25, and said forward end contains a bushing 56. The inner wall of the booster 2! is spaced from the inner end of the chamber l9 to form a substantially circular closed chamber which contains a rotor or detonator carrier 51. The carrier 51, which is best illustrated in Figures 7 and 8, is provided with a tapered end from the upper surface of which extends an integral sleeve or spindle 58 which is journaled in the counterbored rear end of bore 55 to swingably mount the rotor 51 in the chamber l9. As seen in Figures 7 and 8, the rotor 51 is provided with two bores 59 and 60 which extend therethrough from the front to the rear sides thereof. The bore 59 contains a super quick detonator GI and the bore 60 contains a delay detonator 62. The bores 59 and 60 are equidistant radially from the spindle 58 and are cir- The carrier 51 is also provided with a depression or well 63 which is disposed in the enlarged end thereof, between the bores 59 and 66 and which opens outwardly of said end and which is also disposed in axial alignment with the spindle 58 and with a bore 64, which is located therebetween. Well 63 opens outwardly of the upper or forward surface of the rotor 51 and extends to adjacent the bottom or rearsurface thereof, as best seen in Figures 1 and 8. As seen in Figure 1, the lower end of the bore 64 is threaded to receive a closure 65 which forms a seat for an expansion spring 66, the upper end of which bears against a plunger 61. The plunger 61 has a forwardly extending stem which is reciprocally disposed in the restricted forward end of the bore 64 and which projects therefrom and normally bears against the inner end of chamber l 9. Said inner end of chamber I9 is provided with circumferentially spaced indentations, one of which is shown in dotted lines in Figure 1 at 68, for selectively receiving the stem of the plunger 61 when the rotor 51 is moved to an armedposition, as will hereinafter be described. 3 p A continuation of the bore of spindle 58 extends part way through the body of the rotor 51-and the rear end thereof opens into a transversely disposed slot 69, formed in the :bottom part of the rotor 51. A torsional spring, designated generally 16, comprises an elongated strand-of resilient wire having a free end turned back upon itself to form a hook 1|. The strand of wire of the spring 10 extends through the bore 55 and the bore of the spindle 58 and has its hook portion 1| extending intoand; in engagement with the slot 69, the width of which is only slightly greater than the diameter of the wire, for keying the spring 10 to the rotor 51. The opposite end of said strand of wire extends through and is journaled in the bushing '55 and terminates in the slot 12 formed in the forwardly facing shoulder which surrounds the nipple 25. As an alternative, the bushing 56 can be fixed to the spring 10 and rotatably disposed in the bore 55. Said end of the strand of wire is suitably secured to a lever arm 13 which projects laterally therefrom and the free end of which is spring biased toward said strand. As seen in Figure 10, the ends of the slot 12 are indented to receive and engage the resilient free end of the lever arm 13 for latching said arm either in the position, as seen in Figure 10, or in a position in which the arm 13 is disposed at an angle of 180 to its position of Figure 10. 3

The cover l1, which incloses the-arming vane 43, the lever .arm'1-3 and the safety pin 53, is removably held in position. on the housing [6 by a removable band of adhesive tape .14. 7 Cover l1 protects the aforementioned parts during storage and transportation and is removed prior to preparing the fuze I5 for firing. l

Assuming that the.cover H has been removed and that the rotor 51. is in itsintermediate or disarmed position of Figures 1 and 4, the housing I6 is threaded into the forward endof a projectile and connected thereto by a threaded portion l8. To prepare the fuze l5 for firing, the arm 13 is swung from an intermediate position, midway of the ends of the slots 12, in either direction. If it is desired to produce a super quick functioning of the fuze upon impact,

the lever arm 13 is swung tc the leftor clockwise and engaged in th indentation marked SQ, as seen in Figure 10, or if delay functioning of the fuze upon impact is desired, the lever arm is swung to the right or counterclockwise and engaged in the other indentation marked D. Either movement of the lever arm r3 willproduce a 90 torque on the resilient wire strandiand,;assuming that the lever arm 73 is in its position of Figure 10, it will urge the carrier'5l to swing in a clockwise direction from its position ofFigure 4. However, the stem 3| extends into the well 63 to prevent angular movement of the rotor 51 about the axis defined by its spindle 58; The fuze I5 is now ready to function except for removal of the safety pin 53 which is accomplished just previous to insertion of the projectile, containing the fuze, into the mortar tube. Assuming the projectile containing the fuze has been fired and is in flight, the vanes 53 are pitched so that on acceleration of the fuze I5 the'arming vane 43 will rotate in a counterclockwise direction. This will tension the spring 50 to pull the sleeve 38 toward the forward end of the fuze I 5 thereby moving the threaded portion 29 forwardly and into engagementwith the threaded portion 28. The torque of the spring 5!! will exert a torsional strain on the sleev 30 to rotate it counterclockwise, looking from front to rear of the fuze l5, to thereby screw the sleeve 30 throug the threaded sleeve portion 28 and retract the stem 3| forwardly and away from the well 63, in which it is disposed. As the stern 3| moves out of engagement with the well 63 the rotor 5! is released so that the torque exerted thereon by the spring 19 will swing the rotor 51 in a clockwise direction from its position of Figure 4 to move the super quick detonator Bl into alignment with the bore of the spindle or'sleeve 3 i. As the rotor 51 reaches this position, the forward end of the plunger 5'! will be received in one of the indentations 68 for latching the rotor in an armed position. After the threaded portion 29 has moved entirely through the threaded portion 23 the sleeve 30 is released and is free to revolve with the shaft 48 and the primer 32 is disposed adjacent to but still spaced from the tapered projection 49. The springs as and so both function, with the parts thus disposed, as creep springs to prevent the primer 32 and projection $9 for moving toward one another. Upon impact of the arming vane 43 with a target, the shaft til is driven rearwardly against the tension of, springs 44 and 59 to cause projection 49 to strike and detonate the primer 32. The flash therefrom passes through the bore of the stem 3! to ignite the detonator B! which instantaneously ignites the explosive in the cup 23 for detonating the booster 2| and the burster charge, not shown, of the projectile. Should the fuze graze the target, inertia will carry the sleeve 30 forward in the sleeve 26 and against the springs 45. and 553 to detonate the primer 32 by engagement with projection 49.

It will likewise be readily obvious that if the lever arm 13 is moved to engagement with the indentation designated D, that upon retraction of the spindle 3| out of engagement with the carrier 5?, the carrier will be swung in'a counter-, clockwise direction by the oppositely exerted torqu of the spring iii to move the'delay detonator 62 into alignment with the bore of spindle 3i and into the position, as seen in Figure 5. The delay detonator 62 includes a charge of black powder which produces a delay ignition of the charge contained in the cup '2iialto permit penetration of a target before detonation of the projectile.

. As clearl illustrated in Figure 1, the initial position of the threaded portion 29 is to the rear of and out of engagement with the threaded portease-es ut lisestems free rotationer the -sleeveififi in anopposite or clockwise direction so that if propelling gases escaping from the muzzle; of the i 7 tube, from which the projectile isfired, stream past 'theshell and cause the arming van'e to rotate inaclockwise direction, the torque thus produced cannot screw the sleeve 39 into a tight engagement with the sleeve 25 which would prevent-the sleeve as from thereafter being turned in theopposite direction and advance forwardly through the threaded portion 28, and thus pre-' vent arming of the fuze while in flight. Thus by the meansjust described the arming vane is allowed to spin free in a backwarddirection due to the threaded portions 28 and 29 being initially assembled in a disengaged condition. Various modifications and changes are cont'ernplated and may obviously be resorted to, without departing from the spirit and scope of the' inven-.

means being movableout of engagementwith the I carrier during flight of. the fuse, and said. fuze having a flash passage into alignment with which one orthe detonating means is selectively moved by the torsional member, when the carrier one gaging means is retracted out of engagement with the carrier.

2. ,A fuze'as in claim ,1, and an armingvane connected to the earl engaging'meansfor moving said means out of contact with the carrier during flight of the projectile. Y i

3. A 'uze in claim 1, said torsional member e enipri'ising strand of resilient wire rotatably disposed in the housing-and having one end keyed to the carrier, a lever arm projectinglaterally from the opposite end of the strand and from the hous-' ing, and said housing having a slo't in which said lever arm isfmovable said slot having keepers at the ends thereof for releasably engaging-the lever arm whereby a torsional stress in-either= direction can be applied tothe wire strand;

4:. A fuze for nonrotating projectiles comprising a housing, affiring pin slidacly disposed-in the housing, a primer holder containing a primer mounted for movement lengthwise relatively to the'h'ousing and firing pin, a detonator carrier mounted to oscillate-in the housing and containing arcuately spaced detonators, said primerholder'beinginitially disposed within the carrier to retain the 'same in a central 'di'sarmed position, adjustable" spring means for resiliently biasing the carrier for selective movement to position either of the detonators in alignment with' -the i primer after saidnolder isdis'engaged fro'msaidJ carrier, an arming vane connected 'to the firing pin for rotating the firing pin during fiight'of the fuze, and spring means connecting the firing pin and-holder for' retracting the holder out-jof engagement with the carrier when the firing is revolved.

5. A fuze for non-rotating type projectiles} comprising a housing, a detonator rotor arranged to oscillate therein between a first and second" position, said rotor having arcuately spaced detonators contained therein, means holding the rotor in a central position, said means being movable out of engagement with the rotor in response to flight of the fuze, spring means adjustable to resiliently bias said rotor for selective movement in respectively opposite directions toward either said first or said second position for moving a pre-selected one of said detonators into firing position after said rotor is released by said rotor holding means, said rotor holding means comprising a sleeve, a primer disposed in a portion of said sleeve, a shaft journaled in the housing and having one end projecting therefrom, an arming vane keyed to said end for rotating the shaft when the fuze is in flight, the opposite end of the shaft being loosely disposed in the sleeve and in alignment with the primer, a helical spring Wound around the shaft and connected at one end to the shaft and at its opposite end to the sleeve, said sleeve being in threaded engagement with the housing whereby when the arming vane and shaft are revolved the helical spring will exert a torsional stress on the sleeve torotate it and thereby retract it relatively to the rotor, and said shaft being reciprocably mounted in the housing to engage and detonate the primer upon impact of the fuze.

6. In a fuze, a housing having a chamber, a rotor in said chamber pivotable in both directions about an axis fixed with respect to said housing, a spring secured to said rotor, means manually adjustable to stress said spring in either direction to urge said rotor in a corresponding direction, a bore in said housing offset from said axis and opening into said chamber, a sleeve movable axially in said bore from a first to a second position, said sleeve when in said first position engaging and holding said rotor in a central unarmed position and when moved to second position freeing said rotor, and first and second detonators carried by said rotor each said detonator being moved by said rotor into alignment with said sleeve for respective directions of pivoting of said rotor.

7. In a fuze as recited in claim 6, and second means operable in response to movement of said fuze in flight to move said sleeve from first to second position.

8. In a fuze as recited in claim '7, said second means comprising a shaft j ournaled in said housing coaxially of said sleeve and having a portion extending exteriorly of said housing, a vane on said extending portion, and a coil spring wound about said shaft and having one end anchored thereto and its other end fixed to said sleeve.

9. In a fuze as recited in claim 8, there being a threaded connection between said sleeve and said housing whereby said sleeve on rotation is moved to second position.

10. In a fuze, a housing having a central bore, a sleeve in said bore, there being a screw threaded connection between said sleeve and housing whereby on rotation, said sleeve is moved axially of said bore from a first to a second position, arming means engaged and held by said sleeve in unarmed position when said sleeve is in first position, a shaft journaled in said housing in axial alignment with said sleeve, vane means for rotating said shaft in response to flight of said fuze, and a coil spring surrounding said shaft and connected at its one end to said shaft and at its other end to said sleeve.

11. A fuze as recited in claim 10, a tube fixed in said housing, said sleeve fitting said tube and having threads adapted to engage threads of said tube,- said threads being normally disengaged, said spring when tensioned by turning of said shaft drawing said sleeve axially relatively to said tube to positively engage said threads.

12. For use in a non-rotating type projectile, a fuze comprising a housing having a bore and a chamber communicating with one end of the bore, a firing pin slidable in the bore, a rotor pivoted in said chamber on an axis parallel with and offset from the axis of said bore and pivot-- able about said offset axis in both directions of rotation, said rotor having first and second detonators therein, each said detonator being moved into coacting relation with said firing pin when said rotor is rotated in a respective one of said directions from a central position, a normally unstressed spring connected with said rotor, means connected with said spring and manually adjustable to stress said spring to urge said rotor into a selected direction of rotation, and means to maintain said spring in manually stressed condition.

13. In a fuze for a projectile, a housing, an arming device in said housing and movable from a first unarmed position to a second armed position, a tube fixed in said housing, a sleeve mounted for movement axially along said tube and having a portion normally engaging and holding said arming device in first position, a rotatable shaft, means for rotating said shaft in response to passage of said projectile in flight, spring means connecting said shaft and sleeve, there being normally uncoupled threads between said tube and sleeve, said sleeve bein moved axially by said spring means in response to initial rotation of said shaft to bring said threads into threading engagement, further rotation of said sleeve through said spring means moving said sleeve axially along said tube out of contact with said arming device to free said device for movement to second position.

14. In a fuze, a housing, a chamber in said housing, a rotor pivotable in said chamber in both directions about an axis in fixed relation with said housing, a normall unstressed spring attached to said rotor, adjusting means carried by said housing and connected with said spring to stress the same to thereby urge said rotor in either one of two opposite directions of rota tion, means to hold said spring in stressed condition, first and second detonators of different time characteristics carried by said rotor, either of said detonators being moved with said rotor into armed position when said rotor is released for pivotal movement by said spring in a respective direction, means normally locking said rotor in central unarmed position, and means responsive to flight of a projectile carrying said fuze to move said locking means to free said rotor for movement under urge of said spring when stressed.

LYLE K. LILJEGREN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,129,692 Hottinger Sept. 13, 1938 2,397,781 Fischer Apr. 2, 1949 

